Ampex-400-tape-adj维修电路原理图.pdf

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RadioFans.CN 收音机爱 好者资料库 AMPEXMODEL400 MECHANICALADJUSTMENTMANUAL TableofContents Pages SECTIONIGENERAL1-2 SECTIONIIOPERATIONALIRREGULARITIESAND THEIRCORRECTION1-3 SECTIONIIIADJUSTMENTS A.BRAKELEVERPIVOTS1 B.BRAKERELEASEARMRESETSTOP1 C.TRIPLEVERSTOP 1 D.FASTFORWARDANDREWINDHOLDBACK1 E,BRAKES 1 F.MASTERSWITCHADJUSTMENT2 G.PLAYENGAGEADJUSTMENT 2 H.TURNTABLEREVERSINGSWITCH2 I.TURNTABLEMOTORCENTERING J.POWERBOOSTERSWITCHADJUSTMENT K.TAKEUPTENSIONARMTENSION 3 L.PLAY RESISTORSWITCH,RECORDINTER LOCKSWITCH ANDPLAYHOLDBACK ADJUSTMENT M,PLAYTAKEUP ADJUSTMENT N.REELIDLERHEIGHT 4 0,TURNTABLEHEIGHT P.REELSIZESWITCHADJUSTMENT4 Q.CAPSTANIDLERHEIGHT 5 R.CAPSTANTAPEGUIDEHEIGHTS RadioFans.CN 收音机爱 好者资料库 AMPEXMODEL400MAGNETICTAPERECORDER MECHANICALADJUSTMENTMANUAL SECTIONI-GENERAL EachModel400recorderhasbeenverycarefullyadjustedbefore leavingthefactory.Undernormalconditions,theseadjustmentsarequite stableandshouldnotbealtered.However,ifthemachineshouldgetout ofadjustmentthroughunusuallyroughhandlingoraccident,it mayrequire attention.Acompletedescriptionofalladjustmentsis containedinthis manual. DESCRIPTIONOFOPERATION TheModel400machineusesamechanicallinkagetocontrolits variousfunctions.Twomotorsareused,oneforthecapstan drive,the otherfortakeupandrewindoftapeontheturntables.Thelatteroneis engagedwiththeproperturntablebyamechanicallinkageanddrivesit througharubbertireonthemotorpulley.Propertapetensionismain tainedbyafrictionholdback deviceusingfeltpads.Brakingtoallow rapidstoppingoftapemotionisperformedbyanadditionalsetoffelt- linedmechanicalbrakes. Themodeselectorswitch,togetherwiththeFlaybutton,serve tocontroltapemotioninthemachine.Theformerpositionsthemode changecamintoeither Forward,Rewind,orOffpositions.Settingthis caminto theForwardpositionperformsthe followingfunctionsdirections ofmovementarethoseobservedwhenviewingbottomsideoftopplate. 1.BellcrankFig.2-5isrotatedcounterclockwise,moving turntablemotorlinkFig.2_6toleftandtherebycausingmotorpulley toengagetakeupturntable.Simultaneously,rotationofbellcrank. shaft positions turntablereversingswitchFig.2-3,connectingmotor windingssothat rotationindesireddirectionisproduced. , 2.CamfollowerFig.1-2is movedtoleft,causingcamfol l4owerleverFig.1-3torotateslightlyin aclockwisedirectionabout itspivotFig.l-6A.This motionisimpartedtothebrakerelease armthrougb itspivotFig.1-7Acausingthisparttomove tothe right.Iftheakeuptensionarmisinoperating positioneitherby tapebeingpraperLthreadedorbybeingheldoverinsomeother manneragainstspringtension,thetripleverFig.1-5willcatch thetriggeredofthebrakereleasearmFig.1-7andtherebycae positiontobeimpartedthroughthebrakereleaserodstothe l-lO.1-i5.Acol1araterswitchactuator,Fig.1-17onte brake rodFig.1-11alsowilloperatethemasterswitchFig.1-19, ener gizingtheturntablemotor,Fast Forwardoperationwillthenoccur.If the takeuptensionarmisnotinoperating position,thebrakerelease arm willrotatecounterclockwiseaboutitspivot.Nomotion willbeimparted tothebrakerods,brakeswillnotrelease,andmaster switchwillnotclose. Inaddition,themodeselectorwillnotlatchinan operating position Ifthemodeselectorcam isplacedinRewindposition,the motion obe11crankandturntablereversingswitchwillbein aclockwise direc tion.Themotorwillrotateinoppositedirectiontothatdescribed above andwillbeengaged totherewindturntable.Theactionofbrakelinkage willbethesameasforForwardoperation. ShouldthePlaybuttonbedepressedpriortoplacingmodechange caminForwardposition,anadditionalfunctionoccurs.The playengage dogFig.2-2willcatchtheendoftheplayengageleverFig.2-4causing tttorotatein acounterclockwisedirection.This motioninturnwillbe impartedtotheplayengagetierodFig.2-22,movingittotheleft.Since itisattachedtothecapstan idleradjustmentarmFig.2-21,theidler assemblywillrotatebringingthe id.leragainstthecapstan.Inaddition, apinaffixednearthecenteroftheplayengagetierodwilloperatethe playholdbackactuatorFig.2-12,thusincreasingtheholdback effectto maintainpropertapetension.Simultaneously,movementoftheplayhold- backactuatorpositionstherecordinterlockswitch Fig.2-13,andthe playresistorswitchFig.2-10.TheformerinterlockstheRecordbutton ontheelectronicsunit,whilethelatterreducesvoltageontheturntable motorandconsequentlyreducesitstorquetotheamountneededfor proper tapetensioninthePlaymode. Othercontrolsprovidedarethepowerswitch,whichturnsonthe electronicunitsandenergizesthecapstandrive motor,thereelsizeswitch thisunitisaswitchinnameonly;itservesasamechanicallinkagetocon trolpressureonplayholdback,andtape speed switchwhichcontrolspeed ofthedrive motorbyvaryingconnectionofitswindings. SERVICING: beforeproceedingwithadjustments,thetapetransportmechanism andelectronicsshouldberemovedfromthecabinetandthetapetransport mechanismshouldbeplacedupsidedowninthecabinetwithitsfronttoward thefrontofthecabinet.Mostoftheadjustmentscanbemadewiththemachine inthisposition. Therecorderwasdesignedforuseeitherinthehorizontalposition or forrackmounting.Theonlyadjustmentaffectedisthe takeuptension aimtension.Seetakeuptensionarmtension adjustment. AMPEXMODEL400 MECHANICALADJUSTMENTMANUAL SECTIONII OPERATIONALIRREGULARITIESANDTHEIRCORRECTION SnappingthemodeselectorintoForwardpositionwithPlaybutton depressedmaycausethemachinetotripoff. Ifthemachinetripsoffwithnormaloperationofthemodeselector, checkthefollowing: 1.Playengageandmasterswitchadjustments.SeeSectionIII 2.Take-uptensionarmtension.Itmaybetoohigh. 3.Power bcxt switchadjustment. 4.Possiblefailureofmasterswitchorturntablereversing switch. WhenstartinginPlaymode,if excessiveslackdevelopsintapebe tweencapstanandholdbackreeltherebycausingtapetotrackoutofthe capstanengagementandpossiblybreak,thecauseisinsufficientplayhold back. Checkthefollowing: 1.Largereelonpayoutturntablewithreelsizeswitchin smallreelposition. 2.Playholdbackadjustment. Iftakeuptensionarmcontinuestooscillateaftermachineisstarte. inPlaymode,checkthefollowing: 1.Fastforwardaridr.windholdbackadjustment. 2.Takeuptensionrnfor excessivetension. Ifmachinefailstotripoffwhen taperunsout orbreaks,checkthe following: 1.Takeuptensionarmtensionwillbetoolow. 2Takeuptensionarmshaftmaybebindingduetogummycondition Ifso,remove,clean,andreplace.Lubricatewithafewdrops oflightoil. Iftapeconsistentlyscrapestheflangesofeither,reel,check tiri following tee1forbentflanges 2.Differentrollsoftape.Sometapemayhave internalstrains orbeimproperlyslit,causingittowindimproperly. 3.Turntableheight. Iftapedoesnottrackproperlyinreelidlergroove,checkreelidler height.Tape shouldnotbearheavilyoneitheredgeofguidegroove. IfthemachinefailstogointoPlaymodewhenproperlyoperated,but goesinsteadintoFastForward,thecauseisprobablya gummyconditionbe tweenthePlayengagedogandthemodechangecam.Removethemodechange camandwashthestickypartswithsolvent.Placeadroportwooflightoil onthedogpivotwhenreplacing. Ifmachinefailstooperatewhenmodeselectoristurnedtoanopera tingpositionandwhenmodeselectorreturnstooffwhenreleased,checkthe following: 1.Triplever.If gummy,remove,clean,andreplace.Besure thatspringisattached. 2.Triplevers.topadjustment. Ifmachinefailstooperatewhenmodeselectoristurnedtoanopera tingpositionandmodeseiectorremainsinthatposition,checkthefollowing: 1.Masterswitchanditsadjustment. 2,Turntablereversingswitchanditsadjustment. 3.Topplatefuse. 4.Powerswitchandtopplate wiring. Ifbrakingistoosevereorirregularthecauseisprobablyaforeign depositonthebrakedrums.Cleandrumswithcarbontetrachlorid.orother solvent.Thefeltliningsshould functionproperlyafterthedrumshave been cleaned.However,iftheyhaveinsomewaypickedupoiltheyshouldbe.re placed. Iftherubbertiredturntable drivewheelslipsonthebrakedrumin anymode,thesituationshouldbecorrectdimmediatelyastl!rubbertire willbeinjured,andrubberwillbedepositedonthbrakedi1rnscausing brakeandholdbackproblems. Checkthefollowing; 1,Presenceofoilonbrakedrumsor.tire. 2.Turntablemotorcenteringifslippageoccursinonlyone direction 3.Masterswitchadjustment. Iftapetendstowanderupordownfromengementbetweencapstan andcapstanidler,checkthefollowing 1.Capstanidlerheight. 2.Capstantapeguideheight. 3.Playholdbacktensioneithertoogreatortoolight. 4.Playresistorswitchnotcuttingin. 5.Powerboostswitchadjustment. Withthemachineinplaymodethereshouldbeanextrasurgeof powerasthe takeuptensionarmisforciblymovedinagainstthetape.If thissurgedoesnotoccurbeforethemachineshutsoffduetothetakeup tensionarmbeingpushedtowardtherestoroffposition,thenthemachine cannotoperatesatisfactorily.Checktheplayresistorswitchand power boostswitchforproperadjustmentandifnecessarymakefurthercheckto determinethattheswitchesarefunctioning. MODEL400MECHANICALADJUSTMENTMANUAL SECTIONIII A.BRAKELEVERPIVOTS -FIG,1-20 Ifforanyreasonthebrakeleversareremoved,replaceinsame. positionfromwhichtheywereremoved.Tightenlocknut,Fig.1-20, untilit bottomsonthebrakelever,thenbackoffapproximately1/4 turn.Allownodragonthebrakeleveratthis point. B.BRAKERELEASEARMRESETSTOP-FIG1-8 1.Placemodeselectorinoffposition. 2.Loosensecuringscrew,Fig.1-8Aandsetstop sothatthetrigger ingendof thebrakereleasearm9Fig.1-7,isapproximately1/16 fromthebrakereleasearm triggerendstop,Fig.1-7B. 3.Tightensecuringscrewusingcaretoavoidmovingstop asscrewis tightened. C.TRIPLEVER STOP-FIG,1-4 1.Fastentakeuptensionarminoperatin,positionwithScotch tape. 2.Loosenstopsecuringscrew,Fig.1-4A,andturnstoptoaposition thatwillallow3/64to1/16contactbetweenthetriggerendofthe brakereleaselever,Fig.1-7,andthetriplever,Fig.1-5,asth modeselectoristurnedfromofftowardeitheroperatingposit. 3.Tightenstopsecuring screw. D.FASTFORWARDANDREWIND HOLDBACK -FIG.2-8and24 1.Removebrakedrums.Notepositionsothateach drummas placedontheshaftfromwhichitwasremoved. 2.Therewindandfastforwardholdbackarms,Fig.2-8and24. have arestposition2-3/4inchesfromtheturntableshaft,Bend.a. apointclosetotheirmountingstocorrectanymisadjustinent.Be surethat linings contactdrumsevenlyanddonotbearheavilyor heelortoeoflining. E.BRAKES-FIG.1-10and15 1.Swingtakeuptensionarmontopplatetooperating positionandfasten ittherewithScotch tape. . . 2.Turnmodeselectortoeitheroperatingposition. . 3.Loosensetscrewonrewind brakeadjustmentcollar,Fig.1-9,ad adjustbrakeshoetohaveminimumclearancefrom drum,Tighten setscrew.Checktodeterminebrakedoesnot,drag. 4Loosensetscrewontakeupbrakeadjustu,ncllarandadjust.brake shoetoclearbrakedrumby1/32Tietacrew F.MASTERSWITCHADJUSTMENT -FIG.1-19 1.Fastentakeuptensionarminoperating positionwithScotchtape. 2.WiththePlaybuttondepressed,movemodeselectorinforward directionuntilmasterswitch timinblineoncamfollowerarm lines upwiththeedgeofthemodechangecamas showninFig.1-21. 3.Setmasterswitchtoclickatthispointbyadjustingpositionofthe masterswitchactuator,Fig.1-17.Fineadjustmentsmaybemade bybending themasterswitchtongue,Fig. 1-18, slightly. 4.Tightensetscrewinthemasterswitchactuatorandrechecktosee thatthemasterswitchclicksjustastheedgeofthecamlinesup withthemasterswitch timingline.Alwaysperformthischeckin playmode, G,PLAYENGAGEADJUSTMENT Alwayscheckmasterswitchadjustmentseeprecedingparagraph beforemakingthisadjustment. 1.Fastentakeuptensionarminoperating positionwithScotchtape. 2.Adjustcapstan idleradjustmentclamp screw,Fig.2-19,togive mediumdragbetweencapstan idleradjustmentarm,Fig.2-21, andcapstan idler armshaft, 3,DepressPlaybuttonandmovemodeselectorinforwarddirection untilmasterswitchclicks.Shiftthecapstanidlerarm,Fig.2-20, withrespecttothecapstan idleradjustmentarm,Fig.2-21,so thatthecapstan idlerFig.2-17isabout1/64 fromthecapstan, Fig2-16,asthemasterswitchclicks. 4.Securelytightencapstan idleradjustmentarmclamp screw,Fig.2-19. 5.RecheckbydepressingPlaybuttonandmovingmodeselectorin forwarddirection.ThemasterswitchshouldclIckasthecapstan idlerreachesapointabout 1/64fromthecapstan.Donotallow thecapstan idlertotouchthecapstanbeforethemasterswitchclicks H.TURNTABLEREVERSINGSWITCH-FIG.2-3 1.Loosen clampboltonbellcrank,Fig,2-5A; 2.WithmodeselectorinOffposition,rotateswitch switchrotorbladesarecenteredintheswitch, 3.Tightenbellcrankclampbolt. shiftuntilthe Ifthemodeselectordoesnotsecurelylockinbothpositionswhen the takeuptensionarmisheldinoperatingposition,itis probablybe causeofmisadjustmentofthisswitchThestopontheswitch iscausing aprematurestoppageofthecamReadjustslightlytocorrectthiscodi. tion. I.TURNTABLEMOTORCENTERING-FIG, 2 I.Removeturntablemotolink,Fig.26,mbellcrank. Fig.2-5. 2.Holdthe.turntablemotorcenteredaccuratelybetweenthebrake drums.Asimplecenteringjibcouldconsistoftwopiecesof1/16 thickmetalinsertedbetweenbrake drumsandturntablemotortire. 3Revolvetheturntable motor link,Fig2-6,untilitlinesupwiththe outside holeinthebellcrank,Fig2-5 4.Insertturntablemotorlinkfromcastingsideandinstallnewretain ingring J.POWERBOOSTERSWITCHADJUSTMENT-IG.1-16 1.Movethetakeutensionarmfromitsrestoroffpositiontoward thereelidler,Thepowerboostmicroswitchshould clickoropen asthearmguidepassesthrougha linedrawnbetweenthecenterof thereelidlerandthecenterofthe takeuptensionarm bearing. 2.Ifnecessary,adjustbybending themicroswitcharmslightly. K.TAKEUPTENSIONARMTENSION -FIG.1 Theamountoftensiongiventothetakeuptensionarmisimportant. Anamountjustsufficienttotripthemechanismshouldbemaintained. Ifexcessiveitwillcausethemachinetoshutoffduringrewindorfast forwardandcausestartingdifficulties.Forrackmounting,additional tensionhastobeprovidedtocompensatefortheweightofthetensionarm Adjustmentisaccomplishedbylooseningthelocknutatthecamfol lowingarmpivot,Fig. 1-6A,and movingtakeuptensionarmadjustment lug,Fig.1-6,toobtaincorrecttension.Forrackmountingitmaybe necessarytoshortenspringtosecuresufficienttension. L,PLAYRESISTORSWITCH,RECORDINTERLOCKSWITCH ANDPLAY HOLDBACKADJUSTMENT 1.Faste.ntakeuptensionarminoperating positionwithScotchtape. 2.Connectohmmeteracrosstheoutsideterminalsofplayiesistr, Fig.2-15,usingalowresistancerange,todetermineexacttime ofplayresistorswitch action. 3.Playholdbackactuator,Fig.2-12,shouldbeinapproximately normal positiononshaft. . 4,Loosenclampscrewonswitchactuator,Fig.2-25,butmaintain slightdrag. 5Moveswitchactuator,Fig2-25,ontheswitchshaftothatthere sistorcutsinafterthemasterswitchclickasthemodeselector is movedintheforwarddirectionwiththeplaybuttondepressed Resistorshouldcutinwhenpositionofthemodeche.ngecamand camfollowerareas showninFig 3 6WithmachineinPlaymode,readjustplayholdbackactuatoras showninFig2-12untilitpressestheentire surfaceoftheplay hdbackfeltevenlyontheholdbackbrakdrumPlayhod,bak shouldbe4oz,measuredwithrecorderinPlaymodeandfrom N. A. B.hub,Reel sizeswitchshouldbeinlargereelposition. Securelytightenclampscrewwhenadjustmentiscompleted. 7.Recheckplayresistorandrecordswitch,Besuretheplayresistor switchiscorrectlyadjustedasinParagraph5,above,Recordinter lockswitchadjustmentisalsoaccomplishedbythisprocedure. M.PLAYTAKEUPADJUSTMENT Theslideontheplayresistor,Fig.2-15,adjuststheplaytakeup. Movingtheslidetowardthetopplateincreasesthetakeup. Tocheckforpropertension: 1.Fastentakeuptensionarminoperating positionwithScotchtape and withtransportmechanisminnormal positionandpowerconnected. 2.Attachashortpieceofstringabout30tothetakeupreelhubN.A.B. withtheoth